Born: October 21, 1845, in Vilslev, Denmark
Died: April 27, 1923, in Tempe

Niels Petersen was born in a small farming village in southwestern Denmark. He was the sixth child of Peder Mikkelsen and Gunder Marie Nisdatter. When he was 16 years old, Petersen joined the German merchant marines. His first two-year stint on a German ship took him around the world to ports in China and the Philippines. After Germany declared war against Denmark in 1863, he joined the English merchant marines. His journeys for the next couple years took him to the United States and the West Indies. Petersen returned to Denmark for a short time about 1869. In 1870 he set sail for the United States.

In the summer of 1871 he came to Arizona and decided to settle in the Salt River Valley. Just a few years earlier, a group of miners and farmers had started building the first irrigation canals in the valley, and there were plenty of opportunities for an ambitious young man. He probably did some work clearing and leveling desert land. This was hard work with a mule-drawn scraper, pick and shovel, and bare hands, but this was work that everyone did at that time. It was this labor that turned the valley into green, irrigated farm land. Niels helped build the rock and brush diversion dams and the canals and ditches that were all part of the extensive Tempe irrigation system. He also worked for Charles Hayden, operating his general store when Hayden was away tending to his freighting business. But the greatest opportunity for Niels Petersen was the chance to stake a homestead claim in this valley which would soon prove to be one of the most productive agricultural regions in the country.

On July 1, 1874, Petersen filed Declaratory Statement No. 56, claiming 160 acres located in the southeast quarter of section 29. This is the area now roughly bound by Priest, Southern, Alameda, and Interstate-10. Petersen worked on clearing land and planting crops, and completed a two-room adobe house. He also continued working for the Tempe Irrigating Canal Company, and by 1875, he had earned two shares in the company. In the spring of 1878, Niels Petersen became a naturalized United States citizen and filed Homestead Entry No. 55, which was the next step in establishing his homestead.

To claim land under the Homestead Act, one must live upon and make improvements to the land over a period of five years. On May 12, 1883, Niels Petersen filed his final homestead proof. The improvements he had made to the land included two adobe houses, one measuring 16 x 18 feet, and the other, 14 x 20 feet. He had 140 acres planted in wheat, barley, and alfalfa. And he had witnesses to attest that he had fulfilled all of the requirements of the law. Ten days later, the Land Office issued Final Certificate No. 53, which recognized his claim to the land.

During this time, Niels met Isabel Dumphy, who was a teacher at the Tempe Grammar School. They were married about 1884, and Isabel resigned her teaching job and moved into the simple adobe house on the Petersen Ranch. We do not know a lot about Isabel Dumphy Petersen. She was born in Duluth, Minnesota, and came to Tempe about 1878. She apparently died in 1885 after giving birth to a son, John. According to a memoir written by Tempe pioneer Antoinette Miller Hardwicke, after Mrs. Petersen's death, "the child was sent to her people in the east to be cared for." There are indications that within a few months, the infant, John Petersen also died.

This tragedy came at a time when Niels Petersen was emerging as one of the most prominent community leaders and businessmen in Tempe. After fourteen years of hard work he had established a very profitable ranching business. He claimed additional acreage to his homestead, as was allowed by subsequent changes in the law, and he bought out the land holdings of other early pioneer homesteaders who decided to leave Arizona. The Petersen Ranch grew to more than 1,000 acres, and Niels became one of the biggest producers of cattle, hay, and grain in the valley. Besides his personal success, Niels Petersen had also gained the respect and admiration of the people of Tempe. He was known as a well educated, hard working, generous, community minded gentleman. He was elected to a several posts in the 1880s, serving as a Trustee of the Tempe School District and a member of the Maricopa County Board of Supervisors. He also contributed to the commercial and social development of Tempe, playing a leading role in organizing the Tempe Methodist Episcopal Church, the Tempe Lodge of the Independent Order of Odd Fellows, and the Bank of Tempe.

By 1892, Niels Petersen was undoubtedly one of the wealthiest men in the Salt River Valley. The time had finally come for him to build a new house that would reflect the prosperity and social standing that he had earned. He commissioned architect James Creighton to build an elegant two-story Victorian home at the Petersen Ranch (see Petersen House). Creighton was a very well known architect, the designer of some of the most notable residential, commercial, and public building built in Arizona during the territorial period. He had designed the first building for the Territorial Normal School in 1885, the first Phoenix City Hall, the Andre Building in Tempe, the Dominion Hotel in Globe, the Adams Hotel in Phoenix, the Pinal County Courthouse, and Old Main at the University of Arizona.

In August of 1892, while his new house was being built, Niels went on a trip to the East. On September 1, 1892, he married Susanna Decker of South Montrose, Pennsylvania. When he returned to Tempe with his bride, his new Queen Anne Victorian style house was completed. At the time it was considered one of the finest homes in the Salt River Valley.

Niels Petersen went on to accomplish many things. He became treasurer of the Tempe Irrigating Canal Company and president of the Farmers and Merchants Bank. He was elected to serve a term in the Territorial Legislature, 1895-96. In 1913 donated the land and two-thirds of the money needed to build a new Methodist church. Niels Petersen was always regarded as one of Tempe's leading citizens. When he died in 1923 at the age of 78, the town flag was flown at half mast and schools and businesses were closed for his funeral.

Today the Petersen House still stands in its original location, though it is now surrounded by new homes and businesses. It is operated by the Tempe Historical Museum as a historic house museum (see Petersen House Museum).